Advancing cell-based therapies requires an increased understanding of cell trafficking and in vivo function. This core will provide the tools and reagents to monitor cell trafficking, and evaluate the resulting biological changes at the level of cells and molecules in intact animal models. Until recently a fundamental difficulty in the analyses of adoptively transferred cells as therapeutics has been an inability to obtain spatiotemporal information about in vivo processes as they occur. Understanding basic immunologic mechanisms requires that we are able to access this information, in real time, through molecular and cellular imaging modalities. Advanced imaging strategies that provide this information have been developed at Stanford University and these comprise the technologies in the Animal Imaging Core C. The revolutionary technology that underlies this core is based on the observation that low levels of light from internal biological sources can be monitored externally. In this manner, processes labeled through the expression of light emitting enzymes, such as luciferase, can be assessed in vivo. Dr. Christopher Contag, Assistant Professor of Pediatrics, and Microbiology and Immunology is a co-developer of these imaging strategies and will head this core. The imaging core will support the projects in this program project by providing a suite of low light imaging systems, multifunctional reporter genes and immune cell labeling strategies. The approaches to labeling cells in this core are designed to first enable monitoring patterns of cell trafficking and assess molecular changes in intact living animals, and then to facilitate recovery of labeled cells such they can be further analyzed via sophisticated ex vivo assays. The information obtained from this imaging modality will be critical to our understanding of the biological effects and half lives of the cell-based therapeutics that are the focus of projects in this program.